It came to light after the US Navy posted a photo online of the aircraft carrier sailing through the Sunda Strait between Sumatra and Java in Indonesia.

The US military's Pacific Command has now explained that it had to complete the training with Australia, and that the strike group was now "proceeding to the Western Pacific as ordered" and should arrive near the Korean Peninsula early next week.

Video:Trump puts 'doubt' in North Korean minds

North Korea expert Joel Wit, at the 38 North monitoring group, said it raised questions about the Trump administration's credibility.

"If you threaten them and your threat is not credible, it's only going to undermine whatever your policy toward them is," he said.

Despite the embarrassing revelation, US vice president Mike Pence warned North Korea not to test the resolve of America's military, promising it would make an "overwhelming and effective" response to any use of conventional or nuclear weapons.

Image:The supercarrier is now heading to the Western Pacific Ocean

Speaking aboard the USS Ronald Reagan aircraft carrier at the US Yokosuka naval base in Tokyo Bay, Mr Pence said the Trump administration would continue to "work diligently" with allies such as Japan, China and other global powers to apply economic and diplomatic pressure on Pyongyang.